Bash 4.4 alterar o modo de cor vi

Question

Estou usando

+~ $ bash --version 
GNU bash, version 4.4.0(1)-release (x86_64-unknown-linux-gnu)
Copyright (C) 2016 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>

This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

e adicionado ao meu ~/.bashrc

 set -o vi

e no meu /etc/inputrc

set show-mode-in-prompt on
set vi-cmd-mode-string "\e[1;31m:\e[0m"

no entanto, a cor permanece a mesma quando entro no modo de comando. Alguém poderia resolver esse problema. somente o caractere principal muda de + para :